The present invention pertains to automobile safety apparatus and more particularly pertains to a motor vehicle steering column safety device.
Modern vehicles, especially passenger cars, include a variety of passive safety mechanisms; e.g., head restraints, energy absorbing steering columns, and safety glass. However, no other single passive safety feature has had as dramatic effect on reducing the human cost of automobile fatalities and serious injuries as has the air bag. Thus, air bags are being introduced into automobiles at a very rapid rate. Effective Jan. 1, 1998, all U.S. fleet passenger cars must be equipped with air bags. Although analysis shows that air bag systems are working generally as intended, these systems still have some drawbacks.
First, in order to inflate the air bag in a fraction of a second, the inflating gas must be rapidly expanded into the air bag upon collision. To achieve this, some systems use mini chemical explosions which generate extreme heat. Some of these devices follow-up by introducing extremely cold gasses into the reaction so the occupant is not burned by the heat. These explosive gas apparatus require complicated gas storage, separation and flow control means which can sometimes fail. The complex design and manufacture of these systems add significantly to the cost of motor vehicles. As a result, cheaper model cars do not have air bags.
Another problem with the exploding gas systems is the noise. Testing data is replete with instances of vehicle glass being shattered by the blast. Besides frightening the occupants of the vehicle, deployment of the air bag, even in cases where deployment is accidental, can cause personal and/or property damage. The most common alternative to these "hybrid" chemical systems is the sodium azide inflator. Many air bags still use sodium azide inflators, but sodium azide is more toxic and expensive to produce than the hybrid design alternatives.
Third, canisters of these special chemicals along with the air bag often reside within the steering wheel. Thus, one can obtain a completely functional air bag safety device by stealing another's steering wheel. Steering wheel theft is a growing and unacceptable trend which promises only to get worse after Jan. 1, 1998.
Fourth, air bags are, for the most part, engineered for the average-sized-belt-restrained occupant. Thus, pregnant, obese, small and large-sized, and out-of-position occupants are more likely to collide with the steering column and suffer personal injury during collision. Therefore, the provision of a collapsible steering column has been recognized as desirable to provide an added safety factor for all occupants. Some prior systems combine the collapsible steering column and air bag safety devices together, but the prior art depends upon two independent systems: (1) an air bag inflator system, and (2) an independent steering column collapsing means.
Two independent systems take longer to achieve the desired result than a single actuating means. None of the preceding devices collapses the steering column concurrently with inflating the air bag, and the timing of air bag inflation and steering column collapse may be the difference between life and death. Some collapsible steering column safety devices heretofore available use cables and pulleys. Cable and pulley systems can wear out, break, or not respond properly in connection with the inflation of the air bag. The cable may become dislodged from the pulley track, for example.
Other energy absorbing steering columns have also been developed, but upon collision these apparatus deform and (1) make it impossible for the driver to transmit steering torque and/or (2) jeopardize rapid and efficient air bag inflation.
Finally, it is important that a steering column safety device meet original equipment manufacturer's (OEM) specifications and government standards and be economically feasible to implement into all foreign and domestic fleet automobiles.
Therefore, it is highly desirable to provide a new motor vehicle steering column safety device.
It is also highly desirable to provide a new motor vehicle steering column safety device which inflates an air bag faster than prior inflator systems.
It is also highly desirable to provide a new motor vehicle steering column safety device which inflates an air bag without the use of toxic chemicals or chemicals which generate extreme heat and/or cold.
It is also highly desirable to provide a new motor vehicle steering column safety device which does not require complicated gas storage, separation and flow control means.
It is also highly desirable to provide a new motor vehicle steering column safety device which does not utilize a loud mini-explosion in order to rapidly expand the inflator gas into the air bag.
It is also highly desirable to provide a new motor vehicle steering column safety device which collapses the steering column concurrently with inflating an air bag.
It is also highly desirable to provide a new motor vehicle steering column safety device with the inflator gas and gas flow control means contained within the steering column.
It is also highly desirable to provide a new motor vehicle steering column safety device which does not use pulleys, cables and other movable parts which can break or become worn.
It is also highly desirable to provide a new motor vehicle steering column safety device capable of delivering steering torque while collapsing the steering column concurrently with inflating an air bag upon collision.
It is also highly desirable to provide a new motor vehicle steering column safety device capable of damping the force delivered to the steering column by an occupant upon impact.
It is also highly desirable to provide a new motor vehicle steering column safety device which meets all of the original equipment manufacturer's (OEM) specifications and required regulations, can be cheaply manufactured and easily installed into any make and model of vehicle.
It is finally highly desirable to provide a new motor vehicle steering column safety device which meets all of the above desired features.